Uncooked meringues are the simplest and most common, and provide a broad range of textures, from frothy to creamy to dense and stiff. The lightest possible consistency is obtained by first beating the whites to a firm foam and then gently folding in the sugar with a spatula. The sugar dissolves into the existing bubble walls and adds both bulk and cohesiveness to them. The added bulk gives the bubbles more room to slide past each other and creates a soft, frothy consistency suitable for a spread pie topping or for folding into a mousse or chiffon mix, but too fragile to shape. A creamier, firmer consistency results when the sugar is not merely folded in, but beaten in. In this case, the sugar’s added bulk is spread out as the beating further subdivides the bubbles, and the cohesiveness of the sugar-water mixture noticeably tightens the foam’s texture. The longer you beat the egg-sugar mixture, the stiffer it will get and the more finely it can be shaped.